REMAINING-SERVICE-LIFE EVALUATION METHOD FOR METAL PIPE SUFFERING FROM CREEP DAMAGE

摘要

[PROBLEMS] To measure the remaining life of a metal pipe subjected to creep damage without scraping the surface of the metal pipe. (Remedy) In the remaining service life diagnosis method according to the present invention, the residual service life of the metal pipe (1) subjected to creep damage is diagnosed based on a master curve prepared in advance. The master curve is subjected to an internal pressure creep test in a state in which a strip steel (2) made of a metal material having a coefficient of thermal expansion and strength equal to or higher than that of the metal pipe is wound on the outer peripheral surface of the test piece (11) . The master curve shows the relationship between the degree of deterioration of the steel strip and the remaining service life of the metal tube. At the time of diagnosis of the remaining service life, strip steel is wound around the outer circumferential surface of the metal tube under the same conditions as the internal pressure creep test. Then, the degree of deterioration of the steel strip due to the use of the metal tube is measured and applied to the master curve.